The People Behind the Plants: Denny Werner

Denny Werner, NCSUDenny Werner, a Raulston Distinguished Professor at North Carolina State University, enjoys the old-fashioned approach to breeding. Werner uses what he calls “classical techniques.” Werner’s emphasis is variety development by growing out hybrids from controlled crosses.

“Our program grows out large populations in the field where we make selections,” he said. “A lot of hybrids can be obtained using classical techniques, particularly with ornamentals.”

Historically, there haven’t been an abundance of programs dedicated to ornamental plant breeding. Many ornamental cultivars arose due to chance rather than controlled breeding programs, he said.

But Werner’s breeding program at NCSU is making its own history. His current emphasis is on Buddleia and Cercis. He’s looking for particular traits in each crop including leaf variegation, leaf and flower color, and weeping growth habit in Cercis. For Buddleia, he’s interested in flower color, sterile forms, compact growth habit and leaf color.

When he first came to NCSU in 1979, he was breeding peaches. By the mid-1990s, he thought about switching his focus to ornamentals.

“I started teaching plant propagation around that time, and I was influenced by the arboretum at the university,” he said. “I had some informal discussions with J.C. Raulston – he was a champion of Cercis – so I decided to give redbud breeding a shot. That crop has a tremendous amount of genetic variability that is largely unexploited outside the J.C. Raulston Arboretum.”

Werner also had a personal passion for the crop, which is important, he said.

Buddleia was a good choice because it’s a shorter-term crop – about a one-year plant – and it had a presence in the nursery and retail trade, but there were plenty of opportunities for improvements, he said.

His years of breeding fruit and vegetable crops have influenced the way he approaches ornamental breeding.

“I learned the standard breeding procedures and I apply those to ornamentals,” he said. “Working with vegetables and fruits helped shape my big-picture view of breeding.”

Werner selected Buddleia Lo & Behold ‘Blue Chip,’ which was released to retailers in 2009 by Proven Winners ColorChoice. ‘Blue Chip’ is a dwarf variety with heavy branching and a spreading habit, he said. It can easily be kept at 3 feet high. It’s not completely sterile, but it “produces exceedingly less seed than other forms on the market,” he said.

He selected Buddleia ‘Miss Ruby’ for its extremely bright pink flowers. It was also released by Proven Winners ColorChoice. “It’s more vigorous than ‘Blue Chip,’ but less vigorous than other forms on the market,” he said.

He expects to release at least three more Buddleia cultivars during the next three or four years.

Werner found some winners in his redbud block almost a decade ago. ‘Merlot’ is a hybrid with purple leaves. It was released this year by PlantHaven. Werner also selected a purple-leaved weeping variety that PlantHaven will release in another year or two.